This invention relates generally to water recirculation pumps and, more specifically, to sealing devices used in water recirculation pumps.
Water pool apparatuses, such as portable spas, portable pools, in-ground spas, in-ground pools, hot tubs, and recirculating bath tubs are enormously popular. Most such water pool apparatuses have a water recirculation system wherein water within the main water basin is recirculated through a filter and then back into the water basin by a centrifugal pump.
There is a problem with the use of centrifugal pumps for water pool apparatuses. This problem arises from the leakage of water at the impeller shaft pump seal. Such leakage is frequently detrimental to the efficient operation and life span of the pump, especially in water pool apparatuses wherein the recirculating water contains chlorine and/or other corrosive chemicals.
Accordingly, there is a need for a water pool apparatus recirculation pump seal which avoids the leakage problem experienced in the prior art.
The invention satisfies this need. The invention is a pump seal for sealing the impeller shaft of a centrifugal pump, especially centrifugal pumps used to recirculate water in a water pool apparatus. The pump seal of the invention comprises (a) seal housing for surrounding the impeller shaft, the housing comprising a forward end, a rearward end and a reservoir chamber disposed therebetween, the reservoir chamber having a drain port for discharging liquids from the reservoir chamber, (b) a forward sealing seat disposed at the forward end of the seal housing, (c) a forward seal element disposed around the impeller shaft and in abutment with the forward sealing seat, (d) a forward spring for urging the forward sealing element against the forward sealing seat so as to seal the impeller shaft from the flow of liquids therealong, (e) a rearward sealing seat disposed at the rearward end of the seal housing, (f) a rearward seal element disposed around the impeller shaft and in abutment with the rearward sealing seat, and (g) a rearward spring for urging the rearward sealing element against the rearward sealing seat so as to seal the impeller shaft from the flow of liquids therealong.
In a typical embodiment, the drain port on the reservoir chamber is disposed in fluid tight communication with the suction side of the centrifugal pump by a conduit which includes a check valve.
The invention has been found to be highly advantageous for centrifugal pumps used in the recirculation of chlorine-containing water from a water pool apparatus, such as a portable spa, swimming pool or recirculating bath tub.